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8.122. subscribeset(integer, integer, integer, boolean, boolean)

Function Properties

PLPGSQLbigint
subscribeSet (sub_set, sub_provider, sub_receiver, sub_forward, omit_copy) Makes sure that the receiver is not the provider, then stores the subscription, and publishes the SUBSCRIBE_SET event to other nodes. If omit_copy is true, then no data copy will be done.
    declare
    	p_sub_set			alias for $1;
    	p_sub_provider		alias for $2;
    	p_sub_receiver		alias for $3;
    	p_sub_forward		alias for $4;
    	p_omit_copy		alias for $5;
    	v_set_origin		int4;
    	v_ev_seqno			int8;
    	v_rec			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table sl_config_lock;
    
    	raise notice 'subscribe set: omit_copy=%', p_omit_copy;
    
    	-- ----
    	-- Check that this is called on the provider node
    	-- ----
    	if p_sub_provider != getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: subscribeSet() must be called on provider';
    	end if;
    
    	--
    	-- Check that the receiver exists
    	--
    	if not exists (select no_id from sl_node where no_id=
    	       	      p_sub_receiver) then
    		      raise exception 'Slony-I: subscribeSet() the receiver does not exist receiver id:%' , p_sub_receiver;
    	end if;
    
    	-- ----
    	-- Check that the origin and provider of the set are remote
    	-- ----
    	select set_origin into v_set_origin
    			from sl_set
    			where set_id = p_sub_set;
    	if not found then
    		raise exception 'Slony-I: subscribeSet(): set % not found', p_sub_set;
    	end if;
    	if v_set_origin = p_sub_receiver then
    		raise exception 
    				'Slony-I: subscribeSet(): set origin and receiver cannot be identical';
    	end if;
    	if p_sub_receiver = p_sub_provider then
    		raise exception 
    				'Slony-I: subscribeSet(): set provider and receiver cannot be identical';
    	end if;
    
    	-- ---
    	-- Verify that the provider is either the origin or an active subscriber
    	-- Bug report #1362
    	-- ---
    	if v_set_origin <> p_sub_provider then
    		if not exists (select 1 from sl_subscribe
    			where sub_set = p_sub_set and 
                                  sub_receiver = p_sub_provider and
    			      sub_forward and sub_active) then
    			raise exception 'Slony-I: subscribeSet(): provider % is not an active forwarding node for replication set %', p_sub_provider, p_sub_set;
    		end if;
    	end if;
    
    	-- ----
    	-- Create the SUBSCRIBE_SET event
    	-- ----
    	v_ev_seqno :=  createEvent('_schemadoc', 'SUBSCRIBE_SET', 
    			p_sub_set::text, p_sub_provider::text, p_sub_receiver::text, 
    			case p_sub_forward when true then 't' else 'f' end,
    			case p_omit_copy when true then 't' else 'f' end
                            );
    
    	-- ----
    	-- Call the internal procedure to store the subscription
    	-- ----
    	perform subscribeSet_int(p_sub_set, p_sub_provider,
    			p_sub_receiver, p_sub_forward, p_omit_copy);
    
    	return v_ev_seqno;
    end;

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